Patents by Inventor Osamu Kitakami
Osamu Kitakami has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8691402Abstract: A perpendicular magnetic recording medium according to which both the thermal stability of the magnetization is good and writing with a magnetic head is easy, and moreover the SNR is improved. In the case of a perpendicular magnetic recording medium comprising a nonmagnetic substrate (1), and at least a nonmagnetic underlayer (2), a magnetic recording layer (3), and a protective layer (4) formed in this order on the nonmagnetic substrate (1), the magnetic recording layer (3) comprises a low Ku region (31) layer having a perpendicular magnetic anisotropy constant (Ku value) of not more than 1×105 erg/cm3, and a high Ku region (32) layer having a Ku value of at least 1×106 erg/cm3. Moreover, the magnetic recording layer (3) is made to have therein nonmagnetic grain boundaries that contain a nonmagnetic oxide and magnetically isolate crystal grains, which are made of a ferromagnetic metal, from one another.Type: GrantFiled: November 2, 2012Date of Patent: April 8, 2014Assignees: Fuji Electric Co., Ltd., National University Corporation Tohoku UniversityInventors: Osamu Kitakami, Yutaka Shimada, Satoshi Okamoto, Takehito Shimatsu, Hajime Aoi, Hiroaki Muraoka, Yoshihisa Nakamura, Hiroyuki Uwazumi, Tadaaki Oikawa
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Patent number: 8323808Abstract: There is provided a perpendicular magnetic recording medium according to which both the thermal stability of the magnetization is good and writing with a magnetic head is easy, and moreover the SNR is improved. In the case of a perpendicular magnetic recording medium comprising a nonmagnetic substrate 1, and at least a nonmagnetic underlayer 2, a magnetic recording layer 3 and a protective layer 4 formed in this order on the nonmagnetic substrate 1, the magnetic recording layer 3 comprises a low Ku region 31 layer having a perpendicular magnetic anisotropy constant (Ku value) of not more than 1×105 erg/cm3, and a high Ku region 32 layer having a Ku value of at least 1×106 erg/cm3. Moreover, the magnetic recording layer 3 is made to have therein nonmagnetic grain boundaries that contain a nonmagnetic oxide and magnetically isolate crystal grains, which are made of a ferromagnetic metal, from one another.Type: GrantFiled: January 10, 2005Date of Patent: December 4, 2012Assignees: Fuji Electric Co., Ltd., National University Corporation Tohoku UniversityInventors: Osamu Kitakami, Yutaka Shimada, Satoshi Okamoto, Takehito Shimatsu, Hajime Aoi, Hiroaki Muraoka, Yoshihisa Nakamura, Hiroyuki Uwazumi, Tadaaki Oikawa
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Patent number: 8076012Abstract: Disclosed are a magnetic thin film capable of providing a high uniaxial magnetic anisotropy, Ku, while suppressing the saturation magnetization Ms thereof, and a method for forming the film; and also disclosed are various devices to which the magnetic thin film is applied. The magnetic thin film comprises a Co-M-Pt alloy having an L11-type ordered structure (wherein M represents one or more metal elements except Co and Pt). For example, the Co-M-Pt alloy is a Co—Ni—Pt alloy of which the composition comprises from 10 to 35 at. % of Co, from 20 to 55 at. % of Ni and a balance of Pt. The magnetic thin film is applicable to perpendicular magnetic recording media, tunnel magneto-resistance (TMR) devices, magnetoresistive random access memories (MRAM), microelectromechanical system (MEMS) devices, etc.Type: GrantFiled: July 28, 2009Date of Patent: December 13, 2011Assignees: Tohoku University, Fuji Electric Co., Ltd.Inventors: Takehito Shimatsu, Hideo Sato, Osamu Kitakami, Satoshi Okamoto, Hajime Aoi, Hiroyasu Kataoka
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Patent number: 7993762Abstract: The present invention relates to a magnetic thin film containing a L11 type Co—Pt—C alloy in which atoms are orderly arranged, and can realize an order degree excellent in regard to the L11 type Co—Pt—C alloy to achieve excellent magnetic anisotropy of the magnetic thin film. Therefore, in the various application devices using the magnetic thin film, it is possible to achieve a large capacity process and/or a high density process thereof in a high level.Type: GrantFiled: December 4, 2009Date of Patent: August 9, 2011Assignees: Tohoku University, Fuji Electric Device Technology Co., Ltd.Inventors: Takehito Shimatsu, Hideo Sato, Osamu Kitakami, Satoshi Okamoto, Hajime Aoi, Hiroyasu Kataoka
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Publication number: 20110020669Abstract: A magnetic recording medium having excellent stability of recorded magnetic signals and capable of recording magnetic signals by a thermally assisted magnetic recording system in which a magnetic recording layer of the magnetic recording medium contains ferromagnetic crystal grains of a Co—Ni—Pt alloy with a Pt content of 44 at % or more and 55 at % or less and with an atom content ratio: Ni/(Co+Ni) of 0.64 or more and 0.8 or less. The magnetic recording medium has extremely excellent stability of recorded magnetic signals since the Co—Ni—Pt alloy constituting the magnetic recording layer has an extremely high anisotropy field at a normal temperature. Further, the magnetic recording medium can perform signal recording based on the thermally assisted magnetic recording system since the Co—Ni—Pt alloy constituting the magnetic recording layer has a Curie point within an appropriate temperature range.Type: ApplicationFiled: July 21, 2010Publication date: January 27, 2011Inventors: Junichi SAYAMA, Hiroaki Nemoto, Hiroshi Ide, Hiroyasu Kataoka, Nobuyukl Takahashi, Takehito Shimatsu, Osamu Kitakami, Satoshi Okamoto, Hajime Aoi
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Publication number: 20100140727Abstract: The present invention relates to a magnetic thin film containing a L11 type Co—Pt—C alloy in which atoms are orderly arranged, and can realize an order degree excellent in regard to the L11 type Co—Pt—C alloy to achieve excellent magnetic anisotropy of the magnetic thin film. Therefore, in the various application devices using the magnetic thin film, it is possible to achieve a large capacity process and/or a high density process thereof in a high level.Type: ApplicationFiled: December 4, 2009Publication date: June 10, 2010Applicants: Tohoku University, Fuji Electric Device Technology Co., Ltd.Inventors: Takehito SHIMATSU, Hideo SATO, Osamu KITAKAMI, Satoshi OKAMOTO, Hajime AOI, Hiroyasu KATAOKA
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Publication number: 20100055503Abstract: Disclosed are a magnetic thin film capable of providing a high uniaxial magnetic anisotropy, Ku, while suppressing the saturation magnetization Ms thereof, and a method for forming the film; and also disclosed are various devices to which the magnetic thin film is applied. The magnetic thin film comprises a Co-M-Pt alloy having an L11-type ordered structure (wherein M represents one or more metal elements except Co and Pt). For example, the Co-M-Pt alloy is a Co—Ni—Pt alloy of which the composition comprises from 10 to 35 at. % of Co, from 20 to 55 at. % of Ni and a balance of Pt. The magnetic thin film is applicable to perpendicular magnetic recording media, tunnel magneto-resistance (TMR) devices, magnetoresistive random access memories (MRAM), microelectromechanical system (MEMS) devices, etc.Type: ApplicationFiled: July 28, 2009Publication date: March 4, 2010Applicants: TOHOKU UNIVERSITY, FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.Inventors: Takehito SHIMATSU, Hideo SATO, Osamu KITAKAMI, Satoshi OKAMOTO, Hajime AOI, Hiroyasu KATAOKA
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Publication number: 20050181237Abstract: There is provided a perpendicular magnetic recording medium according to which both the thermal stability of the magnetization is good and writing with a magnetic head is easy, and moreover the SNR is improved. In the case of a perpendicular magnetic recording medium comprising a nonmagnetic substratel, and at least a nonmagnetic underlayer 2, a magnetic recording layer 3 and a protective layer 4 formed in this order on the nonmagnetic substrate 1, the magnetic recording layer 3 comprises a low Ku region 31 layer having a perpendicular magnetic anisotropy constant (Ku value) of not more than 1×105 erg/cm3, and a high Ku region 32 layer having a Ku value of at least 1×106 erg/cm3. Moreover, the magnetic recording layer 3 is made to have therein nonmagnetic grain boundaries that contain a nonmagnetic oxide and magnetically isolate crystal grains, which are made of a ferromagnetic metal, from one another.Type: ApplicationFiled: January 10, 2005Publication date: August 18, 2005Inventors: Osamu Kitakami, Yutaka Shimada, Satoshi Okamoto, Takehito Shimatsu, Hajime Aoi, Hiroaki Muraoka, Yoshihisa Nakamura, Hiroyuki Uwazumi, Tadaaki Oikawa
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Patent number: 6623789Abstract: A first thin film including at least one transition metal selected from the group consisting of Co, Fe and Ni, and a second thin film including at least one platinum group element selected from the group consisting of Pt and Pd are prepared. Then, a multilayered structure where said first thin film and said second thin film are stacked is formed. Then, the multilayered structure is heated at the same time or after the formation of said multilayered structure, thereby to counter-diffuse constituent elements of said first thin film and said second thin film and alloy said at least one transition metal and said platinum group element.Type: GrantFiled: June 25, 2002Date of Patent: September 23, 2003Assignee: Tohoku UniversityInventors: Yutaka Shimada, Osamu Kitakami, Satoshi Okamoto, Tomoaki Sakurai
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Publication number: 20030049368Abstract: A first thin film including at least one transition metal selected from the group consisting of Co, Fe and Ni, and a second thin film including at least one platinum group element selected from the group consisting of Pt and Pd are prepared. Then, a multilayered structure where said first thin film and said second thin film are stacked is formed. Then, the multilayered structure is heated at the same time or after the formation of said multilayered structure, thereby to counter-diffuse constituent elements of said first thin film and said second thin film and alloy said at least one transition metal and said platinum. group element.Type: ApplicationFiled: June 25, 2002Publication date: March 13, 2003Applicant: TOHOKU UNIVERSITYInventors: Yutaka Shimada, Osamu Kitakami, Satoshi Okamoto, Tomoaki Sakurai
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Patent number: 6339543Abstract: A lattice shaped underlayer made of a ferroelectric material having a piezoelectric effect is formed on a substrate. On the crossing points of the underlayer magnetic films with a magnetoelastic effect are formed. By applying a voltage to the given column and row of the underlayer, the underlayer is stressed at the crossing point. Then the stress is transmitted to the magnetic film on the same crossing point making the magnetization reverse through the magnetoelastic effect, thus, carrying out writing to the MRAM.Type: GrantFiled: May 30, 2000Date of Patent: January 15, 2002Assignee: Tohoku UniversityInventors: Yutaka Shimada, Valentyn Novosad, Yoshichika Otani, Kazuaki Fukamichi, Osamu Kitakami
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Publication number: 20010050829Abstract: In carrying out recording on a magnetic recording medium having substantially uniaxial oblique magnetic anisotropy to the surface of the medium, magnetic characteristics can be remarkably improved by running a ring head having a high saturation magnetic flux density material only on one side of gap portion in normal direction in respect to the magnetic recording medium with a gap edge of the high saturation magnetic flux density material side being ahead, thereby to carry out recording and/or reproducing.Type: ApplicationFiled: November 17, 1994Publication date: December 13, 2001Inventors: OSAMU KITAKAMI, HIROSHI HIRANO
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Patent number: 6055135Abstract: The present invention aims to provide an excellent exchange coupling thin film consisting of a completely novel material other than FeMn or NiMn and having excellent corrosion resistance and high resistivity, and a magnetoresistive element and a magnetic head each of which include the exchange coupling thin film. The exchange coupling thin film includes an antiferromagnetic film mainly composed of a crystal phase of a body-centered cubic structure and containing Cr and element M where element M contains at least one element of the 3B group elements in the Periodic Table, or Al, Ga or In, and a ferromagnetic film containing at least one of Fe, Ne, and Co, both films being laminated in contact with each other, wherein magnetic exchange coupling is generated in the interface between the antiferromagnetic film and the ferromagnetic film.Type: GrantFiled: March 24, 1997Date of Patent: April 25, 2000Assignees: Alps Electric Co., Ltd., Kazuaki FukamichiInventors: Kazuaki Fukamichi, Yutaka Shimada, Osamu Kitakami, Kim Jek Jun, Hiroko Uyama, Akihiro Makino, Naoya Hasegawa
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Patent number: 5543221Abstract: There is disclosed a magnetic recording medium comprising a non-magnetic substrate, a soft magnetic layer formed on the substrate, with or without a non-magnetic sublayer interposed therebetween, and a perpendicular magneto-anisotropic recording layer laminated on the soft magnetic layer, with or without a non-magnetic intermediate layer therebetween, the soft magnetic layer being composed of material saturation magnetization thereof being higher than at least that of the recording layer, and whose thickness is in the range of from 50 to 1,000 .ANG..Type: GrantFiled: May 17, 1993Date of Patent: August 6, 1996Assignee: Hitachi Maxell, Ltd.Inventors: Osamu Kitakami, Hideo Fujiwara, Yoichi Ogawa
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Patent number: 5496620Abstract: A medium in which a magnetic layer is composed mainly of Co and oxygen and has a principal axis of magnetic anisotropy rising unidirectionally at 20.degree. to 80.degree. to a nonmagnetic substrate surface, the coercive force Hs on the surface side of the magnetic layer is 600 to 2,000 Oe and the coercive force Hb on the substrate interfacial side is less than 600 Oe, the medium being produced by treating a nonmagnetic substrate surface with a plasma in an atmosphere of an inert gas or an oxygen gas, and then depositing an alloy composed mainly of Co on the above plasma-treated nonmagnetic substrate surface while an oxygen gas is introduced into the layer-forming atmosphere.Type: GrantFiled: November 4, 1994Date of Patent: March 5, 1996Assignees: Hitachi Maxell, Ltd., Hitachi Ltd.Inventors: Osamu Kitakami, Kunio Wakai, Kazuetsu Yoshida
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Patent number: 5480694Abstract: A magnetic recording medium comprising alumite made by anodic oxidation of aluminum or an aluminum alloy and comprising fine pores in which a ferromagnetic material is filled, wherein an in-plane remanence is at least 2.5 times greater than a perpendicular remanence and a magnetic recording medium of the above alumite, wherein the magnetic material is at least one material selected from the group consisting of Fe or Co, alloy mainly composed of Fe or Co, an Co or Fe containing a P element, and an alloy mainly composed of Co or Fe and containing the P element.Type: GrantFiled: June 4, 1990Date of Patent: January 2, 1996Assignee: Hitachi Maxell, Ltd.Inventors: Hideo Daimon, Osamu Kitakami, Hideo Fujiwara
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Patent number: 5139884Abstract: Provided according to the present invention are a perpendicular magnetic recording medium filled with a magnetic metal containing Fe as a main component in the fine pores of an alumite formed by anodic oxidation of a surface of an Al or Al alloy substrate, the particles of Fe in the filled magnetic metal being crystallographically discontinuous, and a process for the production thereof.Type: GrantFiled: June 2, 1989Date of Patent: August 18, 1992Assignee: Hitachi Maxell, Ltd.Inventors: Hideo Daimon, Hideo Fujiwara, Yoichi Ogawa, Osamu Kitakami
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Patent number: 5068144Abstract: A perpendicular magnetic recording medium comprising a non-magnetic substrate and a magnetic layer which is formed on at least one surface of the substrate and comprises acicular particles of ferromagnetic metal oriented perpendicularly to a plane of the layer and an organic polymer filled in spaces between the acicular particles so as to surround the acicular particules, wherein a volume content of the organic polymer is about 5 to 55% by volume of the whole volume of the magnetic layer, which medium has not only good recording and reproducing characteristics but also improved durability.Type: GrantFiled: October 1, 1990Date of Patent: November 26, 1991Assignee: Hitachi Maxell, Ltd.Inventors: Osamu Kitakami, Hideo Fujiwara, Kiyotaka Ojima, Youichi Ogawa, Kunio Wakai
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Patent number: 5068152Abstract: A magnetic recording medium comprising a non-magnetic substrate and a magnetic layer composed of a ferromagnetic material having a face-centered cubic structure and at least one of a carbon, silicon, a hydrocarbon compound and an organosilicone compound, provided on the non-magnetic substrate, has a high coercive force, a good head running property and a high durability.Type: GrantFiled: November 22, 1988Date of Patent: November 26, 1991Assignee: Hitachi Maxell, Ltd.Inventors: Tsuyoshi Maro, Osamu Kitakami, Hideo Fujiwara
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Patent number: 5059337Abstract: The present invention provides a novel soft magnetic material superior in corrosion resistance which contains (a) a ferromagnetic metal and (b) a carbide of a ferromagnetic metal and/or a silicide of a ferromagnetic metal with at least one of (c) an amorphous carbon and/or an amorphous silicon and (d) a hydrocarbon polymer and/or a silicone polymer and which contains carbon atoms in an amount of 15 atomic % or less, preferably 9-15 atomic %, preferably prepared by the simultaneous vapor deposition of a ferromagnetic metal and a polymer.Type: GrantFiled: September 21, 1988Date of Patent: October 22, 1991Assignee: Hitachi Maxell, Ltd.Inventors: Tsuyoshi Maro, Osamu Kitakami, Hideo Fujiwara, Kunio Wakai